The startups hail from Seattle to Tel Aviv and are all working on voice-related technologies. Amazon partnered with Techstars to launch the inaugural Alexa Accelerator last year. The companies work out of the Techstars Seattle office for 13 weeks before pitching at a Demo Day on October 9.

Amazon and Techstars, which also runs a separate Seattle accelerator program, invest an initial $20,000 in each company for 6 percent common stock, with potential for an additional $100,000 convertible note.

Participating startups incorporate Alexa, Amazon’s popular artificial intelligence and machine learning-powered voice platform. The accelerator is part of Amazon’s $100 million Alexa Fund, which launched in 2015 and is used by Amazon to invest in companies that will push the boundaries of voice-based interaction. The tech giant has already invested in more than 35 startups as part of the fund. Amazon added another $100 million to the fund last year with a focus on international startups.

Alexa powers Amazon’s Echo smart devices, and can be integrated into other third-party devices. Both the Alexa virtual assistant and Echo devices are two of the company’s most successful products. Amazon is battling other tech giants like Google, Microsoft, and Apple in the competitive voice assistant market, though it has a lead as the first mover.

The Information reported earlier this year about risks that startups take when taking money from Amazon’s Alexa Fund. “While Amazon’s backing helps the startups build their businesses, sometimes Amazon decides to go into the market directly,” The Information reported. “It can either offer to buy the startup or simply make the product itself.”

“We are incredibly excited about the possibilities for this year’s participants, all of whom represent a diverse focus of products, services, and industries, and see Alexa as key to unlocking their full potential,” Adams wrote in a blog post.

The accelerator is managed by Aviel Ginzburg, general partner at Seattle venture capital firm Founders Co-op and co-founder of Simply Measured.

Here are the companies in the new cohort, with descriptions from Amazon:

Helix (Atlanta): Virtual assistant for use in the laboratory sciences.

Imageous (San Jose/Seattle): An AI solution for comfort controls and other space management features in commercial buildings, taking in user requests and making changes to their surrounding environment

Jargon (Seattle): Making the world smaller by removing conversational language barriers by combining the best of cutting-edge technology and human assistance.

Taylor Soper is a GeekWire staff reporter who covers a wide variety of tech assignments, including emerging startups in Seattle and Portland, the sharing economy and the intersection of technology and sports. Follow him @taylor_soper and email taylor@geekwire.com.